The Overland Park, Kan., woman and her husband nearly died four years ago when carbon monoxide silently filled their home. The source was a portable generator they fired up in their garage after one of Kansas City's infamous ice storms knocked out power to their neighborhood.

"There's no smell. You can't feel it. It just overcomes you," Abbott said.

They were lucky. A neighbor found them just in time. But at least two people died and more than 60 others sought emergency care after feeling sickened by deadly fumes linked to portable generators during the 2002 storm.

Citing a rise in carbon-monoxide-related deaths, the Consumer Product Safety Commission last week proposed a new rule that would require manufacturers to expressly warn consumers of serious risks posed by using generators improperly -- such as indoors, in a garage or too close to a house.

Officials say warning labels are a first step that may lead to other protective measures, such as requiring sensors that automatically shut down a portable generator when high levels of gases are detected.

Consumer agencies began documenting a rise in deaths two years ago. But they were spurred to action after hundreds of carbon monoxide poisonings and more than 28 deaths were linked to portable generators after hurricanes Katrina and Rita knocked out power to portions of the South a year ago.

"This became a very serious issue for us when we saw a doubling of deaths," said CPSC spokesman Scott Wolfson. "Then when we went into the hurricane season, more attention was drawn by the tragedies that occurred."

The consumer agency attributed 64 deaths last year to carbon monoxide poisoning linked to portable generators. In one case, five members of a Houston family died. Since 2000, there have been more than 222 related deaths.

The proposed new label would warn: "Using a generator indoors WILL KILL YOU IN MINUTES." There are also drawings showing the wrong way to use the popular alternative power sources. In the past, warnings were often in small print or written only in the operating manual.

Most industry officials support the warnings, though some are uncertain about the need to redesign generators to include shutoff sensors, since they aren't made for indoor use.

"We would strongly support anything that made generators safer," said Dan Sherlock, a marketing official with Honda, which makes some of the most popular models. Sherlock said the market for portable generators has grown rapidly in recent years, in part because of severe storms and rolling blackouts.

Current sales figures for portable generators aren't available. But one earlier study found that between 1999 and 2002, more than 1.7 million portable generators were sold in the United States, with nearly a million bought by consumers.

Portable generators were originally marketed mainly for outdoor work and camping activities. But they became popular with homeowners as alternative power sources during outages. And many companies and suppliers increasingly began advertising them for emergency home use.

Using a generator in an open field, however, is far different from using it to get through a power outage. But many consumers who buy or rent them aren't well versed in how to use them safely.

"You have a lot of people using generators for the first time in an emergency," said Wendy Gifford, director of external affairs for Invensys, a company that makes carbon monoxide alarms.

"They go out and hook them up and don't pay a lot of attention to reading the manual," Gifford noted. They fail to realize that generators produce "lethal levels of carbon monoxide."

Homeowners can lose consciousness before they can react to the gas. For that reason, consumer advocates say, more protection is needed.

Warning labels are a good start, said Donald Mays, product safety director for Consumers Union, publisher of Consumer Reports.

"But clearly carbon monoxide sensing with an automatic shutoff is the way to go," Mays said.

Consumers Union supports a bill introduced by Sen. Bill Nelson, a Florida Democrat, that would require portable generators to have an interlock safety device that can detect carbon monoxide and shut the power off before the invisible gas reaches deadly levels.

Michael Sozan, a spokesman for Nelson, said he is "pressing for a hearing" in the Senate Commerce Committee as early as September.